Normal intervertebral discs between endplates of adjacent vertebrae distribute forces between the vertebrae and cushion vertebral bodies. The spinal discs may be displaced or damaged due to trauma, disease or aging. A herniated or ruptured annulus fibrosis may result in nerve damage, pain, numbness, muscle weakness, and even paralysis. Furthermore, as a result of the normal aging processes, discs dehydrate and harden, thereby reducing the disc space height and producing instability of the spine and decreased mobility. Most surgical corrections of a disc space include a discectomy, which can be followed by restoration of normal disc space height and bony fusion of the adjacent vertebrae to maintain the disc space height.
Other procedures can involve removal of one or more vertebral bodies as a result of trauma, disease or other condition. An implant can be positioned between intact vertebrae to provide support until fusion of the affected spinal column segment is attained.
Access to a damaged disc space or to a corpectomy location may be accomplished from several approaches to the spine. One approach is to gain access to the anterior portion of the spine through a patient's abdomen. A posterior or lateral approach may also be utilized. Postero-lateral, antero-lateral and oblique approaches to the spinal column have also been employed to insert implants. Whatever the approach, there may be a need to re-position and/or extract implants after positioning in the spinal disc space or corpectomy location. There remains a need for improved instruments and techniques for use in any approach that facilitate revision of spinal implants in a space between vertebrae.